Neutral field tray system

ABSTRACT

A neutral field tray includes an attachment portion for removably attaching the tray to a mayo stand, a base coupled to the attachment portion, two sidewalls extending upward from opposite sides of the base, a distal endwall extending upward from a distal end of the base, a cover extending between the sidewalls above the base adjacent the distal endwall, and support for positioning a single instrument above the base with a distal end of the instrument underneath the cover and a proximal end of the instrument elevated relative to the distal end of the instrument. A method is also provided for using the neutral field tray.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Ser. No. 12/430,396, filed Apr. 27, 2009, which is hereby incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates broadly to receptacles used in operating rooms for holding or temporarily storing surgical instruments. More particularly, this invention relates to surgical instrument receptacles used in conjunction with a mayo stand.

2. State of the Art

Instruments used by surgeons during surgical procedures are commonly laid out on a moveable table called a “mayo stand”. A mayo stand includes a vertical leg, a rectangular frame horizontally cantilevered at the upper end of the leg, and a wheeled base at the lower end of the leg to provide mobility to the stand. A removable tray is seated on the frame. A typical mayo stand tray may be 13 inches wide by 19 inches long and is generally supported at its longitudinal ends on the frame.

During a surgical procedure, the tray is covered in a sterile material, and instruments to be used during surgery are placed on the tray. Then, as the instruments are required for the procedure, each is picked up from the tray by the surgeon, or an assistant hands the requested instrument to the surgeon.

SUMMARY OF THE INVENTION

The present invention provides a neutral field tray (NFT) attachable to a mayo stand for supporting a surgical instrument during a variety of surgical procedures, and a method of using the NFT. The surgical instruments used in such procedures include a proximal end defining a handle portion, and a distal end for acting on a patient. Such distal end may include a blade, needle or other sharp.

The NFT includes an attachment portion for removably attaching the NFT to the frame of a mayo stand, a base coupled to the attachment portion, sidewalls extending upward from opposite sides of the base along the length of the base between proximal and distal ends, a distal endwall extending upward from the distal end of the base between the sidewalls, a cover extending between the sidewalls above the base adjacent the distal endwall, and support for positioning the surgical instrument such that handle of the instrument is oriented toward the hand of the medical professional, and the medical professional's hand is protected from the sharp at the distal end of the instrument.

In one embodiment, the attachment portion of the NFT defines a hook or other structure which extends over a portion of the frame of a standard mayo stand such that a mayo tray can be seated on the frame over the attachment portion of the NFT. The attachment portion of the NFT may resiliently clip onto the frame of the mayo stand and/or be sandwiched between the frame and the mayo tray. In addition, the attachment portion of the NFT may define at least one hook which couples the NFT to a portion of the frame.

When mounted to the mayo stand, the NFT allows a doctor or assistant to place the surgical instrument in the NFT with a distal end of the instrument disposed under the cover, and a proximal end of the instrument openly accessible. In addition, the NFT orients the proximal end of the surgical instrument such that the distal end is oriented sloped downward relative to the proximal end. In one embodiment, the base of the NFT is preferably sloped downward at an angle relative to the horizontal frame of the mayo stand when the NFT is attached to the mayo stand. The downward sloping of the base of the NFT ergonomically orients the instrument for insertion and retrieval. In one embodiment, the instrument is preferably elevated relative to the base to facilitate retrieval from the NFT by providing a plurality of longitudinally spaced supports along the length of the base. In another embodiment, the base includes tapered side portions which direct the sharp of the instrument into a protective trough that extends below the floor of the tray.

The mounted NFT allows a surgical assistant to move a surgical instrument from the mayo tray (or other source) to the NFT and position the instrument in the NFT in the orientation described above. A doctor may then remove the instrument from the NFT, perform a surgical procedure, and return it to the NFT in the same manner for either removal and disposal or return to the mayo tray (or other location) by an assistant.

As further discussed below, the structure of the NFT, the positioning of the NFT on the mayo stand relative to a doctor and assistant, and the method employed by the doctor and assistant in using the NFT all reduce the risk of injury to the doctor, assistant, patient, and any others present in the operating room.

Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an operating table and partially exploded mayo stand and tray positioned about the operating table.

FIG. 2 is a mayo stand with a neutral field tray attached thereto according to the invention.

FIG. 3A is an enlarged view of the neutral field tray of FIG. 2 attached to a sidewall of the mayo stand and showing longitudinally displaced ridges supporting a surgical instrument.

FIG. 3B is an end view of the neutral field tray with proximal ridges defining curved grooves and a distal ridge defining a straight groove.

FIG. 3C illustrates the ridges of FIG. 3B with a syringe placed therein.

FIG. 3D illustrates the ridges of FIG. 3B with a scalpel placed therein.

FIG. 4 is a side view of the attachment portion of the neutral field tray of FIG. 2 sandwiched between the mayo tray and the sidewall of the mayo stand.

FIG. 5 is a side view of the neutral field tray of FIG. 2 assembled with the mayo stand and a mayo tray.

FIG. 6 is a side view of another embodiment of the neutral field tray of the invention in which the attachment portion defines hooks which hook onto a mayo stand.

FIG. 7 is an illustration of an embodiment of the neutral field tray as part of an operating room setup.

FIG. 8 is a view of yet another embodiment of the neutral field tray in which the attachment portion extends from the cover of the tray.

FIG. 9 is an illustration of an embodiment of the neutral field tray of FIG. 8 as part of an operating room setup.

FIG. 10A is an illustration of an assistant's hand placing a surgical instrument into the neutral field tray.

FIG. 10B is an illustration of the surgical instrument supported inside the neutral field tray.

FIG. 10C is an illustration of a doctor's hand removing the surgical instrument from the neutral field tray.

FIG. 11 is a distal end view of another embodiment of a neutral field tray, wherein the tray is shown oriented at an orientation when mounted to the mayo stand; i.e., in use.

FIG. 12 is a proximal end view of the neutral field tray of FIG. 11, wherein the tray is shown at the same orientation as FIG. 12.

FIG. 13 is a proximal end view of the neutral field tray of FIG. 11, wherein the tray is shown rotated downwards out of its mayo stand mounted orientation.

FIG. 14 is a side elevation view of the neutral field tray of FIG. 11, wherein the tray is shown oriented at the same orientation as FIG. 12.

FIG. 15 is a rear perspective view of the cover and attachment portion of the neutral field tray of FIG. 11.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to FIGS. 1-4, a first embodiment of a neutral field tray (NFT) 10 is shown attached to a mayo stand 12 for supporting a surgical instrument 14 during a variety of surgical procedures.

The mayo stand 12 (FIG. 1) to which the NFT 10 attaches has a base 11 with wheels 19, a vertical leg 13 extending upward from the base 11, and a generally horizontal rectangular frame 15 attached to the vertical leg 13. The frame 15 has an upper surface 15 a and a lower surface 15 b. The frame 15 horizontally supports a mayo tray 17 a (FIGS. 1, 5-6) or table 17 b (FIG. 4), which rests on the upper surface 15 a of the frame 15, and is used by scrub nurses or other assistants to hold/support instruments and supplies during surgery. The mayo stand 12 and horizontal tray 17 a or table 17 b thus provide a stable horizontal surface that is movable relative to an operating table 21 while remaining at a uniform height above the operating table 21.

Referring primarily to FIG. 2, the NFT 10 includes an attachment portion 16 for removably attaching the NFT 10 to the mayo stand 12, a base 18 coupled to the attachment portion 16, sidewalls 20 extending upward from opposite sides of the base 18 along the length of the base between proximal and distal ends (18 a, 18 b), a distal endwall 22 extending upward from the distal end 18 b of the base 18 between the sidewalls 20, a cover 24 extending between the sidewalls 20 above the base 18 adjacent the distal endwall 22, and support 26 (FIGS. 3A-3D) for positioning the surgical instrument 14 above the base 18.

The NFT 10 is either a single molded unit or multi-component unit made from a preferably firm plastic, paper, cardboard or other cellulose-based materials, or other inexpensive but sufficiently stiff material (i.e., to be shape retaining) which is safe for use during operating procedures and preferably sufficiently inexpensive to be disposable on a single-use basis. The NFT 10 is sized to accommodate typical sharp instruments used in the operating room which are potentially dangerous for hand-to-hand transfer, such as scalpels, needles, and other instruments typically used during surgical procedures. The base 18 of the NFT 10 is preferably approximately ten inches long and four inches wide, as such will accommodate a single instrument as well as access to such instrument by a doctor, though other suitable dimensions may be used. The sidewalls 20 of the NFT 10 are preferably 2 inches high relative to the base 18 and may be angled inward toward the center of the base 18. As shown in FIGS. 2 and 3A, the top of the NFT 10 is preferably open except for the cover 24 adjacent the distal endwall 24. The base 18, sidewalls 20, distal endwall 22, and cover 24 together define a box portion which protects the hand of a doctor or assistant from accidental contact with the sharp distal end 14 b of the surgical instrument 14, and a proximal opening allows the instrument 14 to be removed from the NFT 10. To this end, the cover 24 is preferably situated close enough to the base 18 to limit entry of an adult human hand into the box portion defined by the base 18, sidewalls 20, distal endwall 22, and cover 24; i.e., to prevent human hand contact with the sharp at the distal end of the instrument.

The attachment portion 16 of the NFT 10 extends from one of the sidewalls 20 and defines a channel 30 which clips onto a sidewall 23 of the frame 15 of the mayo stand 12. The channel 30 is preferably defined small enough to prevent the NFT 10 from rotating off of the sidewall 23 (e.g., the narrow channel 30 and fairly rigid inner side 33 of the attachment portion 16 maintain the NFT 10 attached to the sidewall 23 under the force of gravity). For example, when the attachment portion 16 of the NFT 10 is clipped onto the sidewall 23 of the mayo stand 12, gravity will pull the NFT 10 downward. The top edge 25 of the sidewall 23 will catch in the corner 27 and the NFT 10 will rotate about the top edge 25 in the direction of the arrow 35 until the outer side 37 of the attachment portion 16 contacts the sidewall 23, at which point the NFT 10 will be anchored to the sidewall 23. If the channel 30 is very narrow (roughly equal to the width of the top edge 25) then the NFT 10 will not rotate at all about the sidewall 23. Further, the channel 30 can be sized slightly narrower than the width of the sidewall 23, and the inner side 33 and adjacent side wall 20 can be flexed relative to each other to seat over the sidewall 23 and then be resiliently retained on the sidewall 23 in an interference fit.

As most clearly shown in FIGS. 4-5, the NFT 10 may also be supported by the horizontal table 17 b (or tray 17 a), the weight of which sandwiches the top portion 31 of the attachment portion 16 of the NFT 10 between the table 17 b and the sidewall 23 of the frame 15. As shown, the attachment portion 16 also preferably defines an inner flange 34 disposed underneath and in close proximity to or touching the mayo tray 17 a or table 17 b. When assembled to the frame, the table 17 b preferably maintains the top portion 31 generally parallel with the table 17 b and also optionally contacts the top of the inner flange 34 of the attachment portion 16. It will be appreciated that such a configuration prevents significant rotation of the NFT 10 about the sidewall 23. Additionally, it will be appreciated that sterile material which is typically placed over the mayo table 17 b and tucked under the table 17 b will help to hold the NFT 10 in place.

Turning to FIG. 6, in one embodiment, the attachment portion 16 of the NFT 10 may define at least one hook 40 which catches on or extends slightly below the bottom of the frame 15 of the mayo stand 12 when the NFT 10 is attached to the frame 15.

Turning back to FIGS. 2 and 3A, once mounted to the mayo stand 12, the NFT 10 allows a doctor or assistant to place the surgical instrument 14 in the NFT 10 with a distal end 14 b of the instrument disposed under the cover 24, and a proximal end 14 a of the instrument elevated relative thereto. The base 18 of the NFT 10 is preferably sloped downward at an oblique angle of 10-40 degrees relative to the horizontal frame 15 of the mayo stand 12 when the NFT 10 is attached to the mayo stand 12. The downward sloping of the base 18 of the NFT 10, which preferably orients the distal end of the base 18 and support 25 below the lower surface 15 b of the frame, ergonomically orients the instrument 14 for insertion and retrieval.

The base also includes a support 25 (FIG. 3A) to elevate the instrument 14 relative to the base to facilitate manipulating instrument in the NFT. The support 25 preferably comprises longitudinally displaced ridges 26 which define grooves 42 shaped to receive the handle 29 and/or body 39 of the surgical instrument 14, as well as curved top surfaces 44 on opposite sides of the respective grooves 42 which slope downward toward the respective grooves 42. The ridges 26 support the surgical instrument 14 above the base 18 so that a person retrieving the instrument 14 from the NFT 10 can more easily secure the instrument 14 with his or her fingers. At least two to four ridges 26 approximately ⅛″ high relative to the base 18 are preferably provided, though other numbers and heights may be used. The grooves 42 and curved top surfaces 44 limit lateral movement of the surgical instrument 14 once it is positioned in the NFT 10 within the grooves 42. In addition, the supports may be of different sizes to supplement (or be used instead of) the angle of the base relative to the frame. For example, if larger supports are used at the proximal end and smaller supports are used at the distal end, such will have the effect of positioning the instrument in a distal end sloped down orientation. The slope of the base 18 and/or the configuration of the support 25 provides that the distal end of the instrument 14 is gravity fed toward the end wall 22 of the tray.

While general use grooves 42 are shown in FIG. 3A, the grooves 42 of a particular ridge 26 may vary in size and shape according to the location of the particular ridge 26 along the base 18 of the NFT so as to accommodate the instrument(s) 14 which will be used by the doctor for a given surgical procedure. For example, as shown in FIG. 3B, the proximal-most and central-most ridges 26 a, 26 b each define a curved groove 42 a, 42 b and the distal-most ridge 26 c defines a straight groove 42 c. The grooves may extend partially through the supports (e.g., FIGS. 3B-3D) or extend all the way through to the base of the tray (142 c in FIG. 8).

As shown in FIG. 3C, when a syringe 41 is placed within the ridges 26 a, 26 b, 26 c, the wider piston pump of the syringe rests on and is supported within the proximal curved grooves 42 a, 42 b, and the needle of the syringe extends through the distal groove 42 c, which is preferably a vertical slot. The curved proximal grooves 42 a, 42 b prevent lateral movement of the syringe within the NFT 10.

As shown in FIG. 3D, when a thin scalpel 43 is placed within the ridges 26 a, 26 b, 26 c, the distal slot 42 c at the distal end of the NFT 10 orients the blade and handle portion of the scalpel 43 longitudinally along the NFT 10 with its thickest dimension transverse relative to the base 18 of the NFT 10 (e.g., the distal slot 42 c preferably defines a channel smaller than the thickest dimension of the scalpel 43, and thus does not allow the scalpel 43 to be rotated ninety degrees or to be moved laterally).

Turning to FIG. 7, the mounted NFT 10 allows an assistant 50 to move a surgical instrument from a store 48 of instruments on the mayo tray 17 b to the NFT 10 and position the instrument in the NFT 10 in the orientation described above. A doctor 52 may then remove the instrument 14 from the NFT 10, perform a surgical procedure, and return it to the NFT 10 in the same manner for removal and disposal or return to the mayo tray 17 b by the assistant 50. At no time is the instrument passed directly from hand-to-hand between doctor and assistant. The NFT 10 thus creates a “neutral field” between the doctor 52 and assistant 50 as further discussed below.

Turning to FIG. 8, in another embodiment, a neutral field tray (NFT) 110 has an attachment portion 116 which extends from a proximal end 124 a of the cover 124 to a distal flange 134. In this embodiment, the NFT 110 is still preferably formed as a single piece of material with the attachment portion 116 defining a channel 130 extending in a direction transverse to the longitudinal direction of the NFT 110 and bounded at the bottom by the top of the cover 124. The NFT 110 has a flared proximal opening with sidewalls 120 which curve at the top to create rounded edges. The NFT 110 clips to a sidewall 123 of the mayo stand 112. The channel 130 is preferably defined small enough to prevent the NFT 110 from rotating off of the sidewall 123. In this embodiment, the channel 130 is preferably sized smaller than the height of the sidewall 123, and the attachment portion 116 can be flexed relative to the cover 124 to clip the NFT 110 to the sidewall 123 with sufficient force to hold the NFT 110 in place. As discussed above with respect to FIGS. 4 and 5, the NFT 110 may be held by a horizontal table or tray, the weight of which sandwiches the attachment portion 116 between the table and the sidewall of the frame. Additionally, sterile material placed over the table may grip a proximal wall 116 a of the attachment portion 116.

Turning to FIG. 9, the NFT 110 of FIG. 8, when mounted to the mayo stand 112 in an operating room layout, orients the medical instrument 114 with a proximal end 114 a in very close proximity to the doctor 152 for easy access.

Referring now to FIGS. 11 through 15, yet another embodiment of a neutral field tray (NFT) 210 is shown. NFT 210 shown includes three discrete elements: a tray 215, a tray cover 224 extending over a portion of the tray 215, and an attachment portion 216 which is connected to the cover 224 for coupling the NFT 210 to a mayo stand. Alternatively, the NFT 210 may be constructed as a unitary structure from a single piece of material, from two elements or from more than three elements.

The tray 215 includes a base or floor 218, side walls 220, and a distal end wall 222. The floor 218 slopes down from the side walls 220 toward a medial portion of the tray, and also tapers in width toward the distal end wall 222. The floor 218 also defines a central trough 226 of preferably uniform width and which gradually deepens toward the distal end wall 222. The trough 226 is sized to accommodate a single surgical instrument at a time, such as a scalpel 228, in a stable and readily accessible orientation. For example, scalpel 228 has a handle 230 with a generally rectangular cross-section, i.e., with a height that is substantially greater than its width. The trough 226 is sized to receive the scalpel handle 230 such that the blade 232 at the distal end of the scalpel 228 is retained in an upright orientation. The depth of the trough at the proximal end 234 of the tray is shallow (or the trough may terminate prior to the proximal end) such that the proximal handle 230 a is exposed and properly oriented for easy grasp by the surgeon. Meanwhile, the distal trough 226 b is preferably sufficiently deep to recess the entirety of the blade 232 below the floor 218. Due to the slope of the floor 218 downward from the sidewalls 220 and obliquely angled downward relative to the horizontal frame, the instrument 230 is gravity fed from the floor into the trough 226 (with the handle 230 a oriented upright and the blade 230 b always situated within the recess of the trough) and with the distal blade end 230 b of the instrument moving to the distal end of the trough. Other instruments are similarly accommodated. For example, when a syringe is located into the NFT 210, the trough is sized to stably support the barrel of the syringe, while the sharp is recessed within the trough in a safe manner below the remainder of the floor.

The cover 224 extends between the side walls 220 above the floor 218 adjacent from approximately midway along the proximal-distal dimension of the side walls 220 to the end wall 222. The cover 224 includes shoulders 240 situated to seat about an upper portion of the side walls 220, as well as tabs 242 that engage holes 244 in side walls 220 of the tray to stably lock the cover to the tray 215. The cover 224 includes a central opening 246 leading into a slot 248.

The attachment portion 216 is attached to the cover 224 via the opening 246 and slot 248. The attachment portion 216 includes a lower end 250 defining deep recesses 252 extending into laterally extending sides 254 of the lower end 250 so that the lower end assumes a squat I-beam shape. The lower end 250 is received through the opening 246 in the cover 224 and portions of the cover on each lateral side of the slot 248 engage within the recesses 252 to form an interference fit that secures the attachment portion 216 to the cover 224. The attachment portion includes a J-hook 256 extending upward from the lower end 250. The J-hook 256 is adapted in size and shape to seat over the horizontal frame 15 of a mayo stand (FIG. 1). Alternatively, different structure, such as a clip, can be provided to the attachment portion to otherwise engage the frame 15 of the mayo stand. Moreover, the attachment portion may connect to the side walls, rather than the cover (as described above), with the J-hook or other structure appropriately oriented to couple the tray to the frame of the mayo stand. The J-hook 256 extends at an oblique angle α relative to the cover 224 (e.g., 40° to 75°, and more preferably 60°) so that bottom of the trough 226 in the floor 218 of the tray is oriented at an oblique angle β relative to a horizontal plane (e.g., 20° to 45°, and more preferably 30°). In this manner the handle 230 of the surgical instrument (e.g., scalpel 228) is oriented upwards at a corresponding ergonomically advantageous angle, while the sharp 232 of the instrument is oriented downward.

Turning to FIGS. 7, 9, and 10A-10C, one preferred protocol for using the NFT 10 (or 110 or 210) is as follows. The assistant 50 uses his hand 60 to move a surgical instrument 14 from the mayo tray 17 b (or other source) to the NFT 10 and position the instrument 14 in the NFT 10 with the distal end 14 b of the instrument disposed under the cover 24. As described above, the instrument 14 is then gravity fed to be situated upright with the sharp 14 b located under the cover 24 of the NFT. The doctor 52 then uses his hand 62 to remove the instrument 14 from the NFT 10 and perform a surgical procedure with the instrument 14 on a patient 54. The doctor 52 then returns the instrument 14 to the NFT 10 and the instrument 14 is positioned within the NFT 10 with the distal end 14 b of the instrument disposed under the cover 24. The assistant then removes the instrument 14 from the NFT 10, ready to present the next instrument into the NFT 10 upon request by the doctor 52. The method is repeated until the surgical procedure on the patient 54 is completed.

As shown in FIGS. 10A-10C and 3A-3D, the size of the NFT 10 and the support 25, as shown by the ridges 26 a-26 c and grooves 42 a-42 c (or via trough 226 in FIGS. 12-14), are preferably configured to receive at most one surgical instrument 14 at a time. This eliminates any possible confusion or injury to the doctor 52, assistant 50, or patient 54 which might otherwise occur if multiple instruments were left in the NFT 10.

The fixed location of the NFT 10 relative to the doctor 52 and assistant 50 facilitates the surgical procedure and reduces the risk of injury. The location of the NFT 10 remains unchanged throughout the procedure.

The protection of the sharp distal end 14 b of the surgical instrument 14 by the cover 24, the positioning of the NFT 10 on the mayo stand 17 b between the doctor 52 and assistant 50, and the employment of the method discussed above for using the NFT 10 facilitates transfer of instruments by at least reducing the risks of instruments being dropped during transfer and increases safety in the operating room by reducing the risk of doctors and their assistants from being punctured by the sharps of instruments during instrument transfer.

There have been described and illustrated herein several embodiments of a NFT and methods of using the same. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, while particular shapes and dimensions of a neutral field tray have been disclosed, it will be appreciated that other shapes and dimensions may be used as well. In addition, while longitudinally displaced ridges have been disclosed for supporting a surgical instrument, it will be appreciated that other types of support may be used. Also, while particular angles have been disclosed for orienting the base of the field tray relative to the mayo stand, and for orienting a surgical instrument, it will be recognized that other angles may be used as well. Furthermore, while specific positioning of a neutral field tray in an operating room relative to a doctor and an assistant has been disclosed, it will be understood that other layouts in an operating room can be similarly used. Also features shown with respect to one NFT can be used in combination with the other. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as claimed. 

1. A neutral field tray attachable to a mayo stand and for use with a surgical instrument having a proximal end defining a handle, a distal end with an exposed sharp for acting on the patient, and a longitudinal axis extending between said proximal and distal ends, the mayo stand having a vertical leg, a rectangular frame horizontally cantilevered at the upper end of the leg, the frame having an inner surface, an outer surface parallel to the inner surface, an upper surface, and a lower surface parallel to the upper surface, the lower surface defining a perimeter, and a wheeled bottom at the lower end of the leg to provide mobility to the stand, the neutral field tray comprising: a base having a proximal end and a distal end and defining a length between said proximal and distal ends; two sidewalls extending upward from opposite sides of said base between said proximal and distal ends, said base having a downward slope away from at least one of said sidewalls, said slope oriented transverse to said length of the base; one and only one instrument trough extending parallel to the length of the base, said trough provided recessed relative to the base and sized and configured to support at most a single surgical instrument with the distal end of the instrument at a distal end of said trough and a proximal end of the instrument at a proximal end of said trough, said proximal end of said trough being open; a distal endwall extending upward from said distal end of said base between said two sidewalls; a cover extending between said sidewalls above said base and adjacent said distal endwall; and an attachment portion for removably attaching said tray directly to the frame of the mayo stand, wherein said trough and said attachment portion are fixed in orientation relative to each other such that when said attachment portion is directly attached to the frame of the mayo stand, said distal end of said trough is located vertically below the lower surface of the frame.
 2. A neutral field tray according to claim 1, wherein: said base slopes medially downward from said two sidewalls toward a medial portion of said base.
 3. A neutral field tray according to claim 2, wherein: said instrument trough is located at said medial portion of said base.
 4. A neutral field tray according to claim 1, wherein: when said attachment portion is oriented as it is when attached to the frame of the mayo stand, and when the instrument is placed on said base, the base is shaped to gravity feed the instrument from said base into said trough.
 5. A neutral field tray according to claim 1, wherein: a depth of said trough is shallower at said proximal end of said trough.
 6. A neutral field tray according to claim 1, wherein: a depth of said trough becomes gradually shallower toward said proximal end of said trough.
 7. A neutral field tray according to claim 1, wherein: said trough has a planar lower surface.
 8. A neutral field tray according to claim 1, wherein: said trough limits lateral movement of the surgical instrument when the surgical instrument is placed therein.
 9. A neutral field tray according to claim 1, wherein: said attachment portion is a resilient plastic hook.
 10. A neutral field tray according to claim 9, wherein: said hook is sized and shaped to snugly engage the inner and outer surfaces of the frame of the mayo stand.
 11. A neutral field tray according to claim 1, wherein: said attachment portion is fixed in orientation relative to said base.
 12. A neutral field tray according to claim 11, wherein: when said attachment portion is directly attached to the frame of the mayo stand said proximal end of said trough is elevated relative to said distal end of said trough.
 13. A neutral field tray according to claim 11, wherein: said trough has a bottom surface, and said attachment portion is adapted to orient said bottom surface of said trough at an angle 20° to 45° relative to a horizontal plane.
 14. A neutral field tray according to claim 11, wherein: said attachment portion attaches to said cover.
 15. A neutral field tray according to claim 1, wherein: said attachment portion is configured to situate said cover lower than the lower surface of the frame.
 16. A neutral field tray according to claim 1, wherein: said attachment portion is configured to situate a portion of said tray within a footprint of the perimeter of the frame when attached to the frame.
 17. A neutral field tray according to claim 1, further comprising: said surgical instrument located within said trough.
 18. A neutral field tray according to claim 17, wherein: said sharp of said instrument is fully recessed in said trough.
 19. A neutral field tray according to claim 18, wherein: said handle of the instrument is at least partially protruding from said trough.
 20. A neutral field tray according to claim 1, wherein: said proximal end of said base defines a first concave shape in a cross-section transverse to said length, and said distal end of said base defines a second concave shape in a cross-section transverse to said length, said first concave shape being larger and shallower than said second concave shape.
 21. A neutral field tray according to claim 20, wherein: said first concave shape is a first V-shape, and said second concave shape is a second V-shape.
 22. A neutral field tray according to claim 20, wherein: said distal end of said base has increased concavity relative to said proximal end of said base in a direction transverse to said length of said base.
 23. A neutral field tray according to claim 1, further comprising: said mayo stand, wherein said neutral field tray is mounted to said frame of said mayo stand with at least a portion of said tray extending at least one of (i) within a footprint defined by said perimeter of said frame of said mayo stand and (ii) below said lower surface of said frame.
 24. A neutral field tray according to claim 23, wherein: said neutral field tray is mounted to said frame of said mayo stand with at least a portion of said tray extending both (i) within said footprint and (ii) below said lower surface of said frame.
 25. A neutral field tray according to claim 23, further comprising: said surgical instrument located within said trough.
 26. A neutral field tray attachable to a mayo stand and for use with a surgical instrument having a proximal end defining a handle, a distal end with an exposed sharp for acting on the patient, and a longitudinal axis extending between said proximal and distal ends, the mayo stand having a vertical leg, a rectangular frame horizontally cantilevered at the upper end of the leg, the frame having an inner surface, an outer surface parallel to the inner surface, an upper surface, and a lower surface parallel to the upper surface, the lower surface defining a perimeter, and a wheeled bottom at the lower end of the leg to provide mobility to the stand, the neutral field tray comprising: a base having a proximal end and a distal end and defining a length between said proximal and distal ends; two sidewalls extending upward from opposite sides of said base between said proximal and distal ends, said base having a downward slope away from at least one of said sidewalls, said slope oriented transverse to said length of said base; one and only one instrument trough extending parallel to said length of said base, said trough provided recessed relative to said base and sized and configured to support at most a single surgical instrument with the distal end of the instrument at a distal end of said trough and a proximal end of the instrument at a proximal end of said trough, said proximal end of said trough being open; a distal endwall extending upward from said distal end of said base between said two sidewalls; a cover extending between said sidewalls above said base and adjacent said distal endwall; and an attachment portion for removably attaching said tray directly to the inner and outer surfaces of the frame of the mayo stand, wherein said trough and said attachment portion are fixed in orientation relative to each other such that when said attachment portion is directly attached to said frame of the mayo stand, said distal end of said trough is located vertically below the lower surface of the frame and said proximal end of said trough is located higher than said distal end of said trough.
 27. A neutral field tray according to claim 26, wherein: said distal end of said trough is located within a footprint of the perimeter of the frame.
 28. A neutral field tray according to claim 26, wherein: said proximal end of said base defines a first concave shape in a cross-section transverse to said length, and said distal end of said base defines a second concave shape in a cross-section transverse to said length, said first concave shape being larger and shallower than said second concave shape.
 29. A neutral field tray according to claim 28, wherein: said first concave shape is a first V-shape, and said second concave shape is a second V-shape.
 30. A neutral field tray according to claim 26, wherein: said distal end of said base has increased concavity relative to said proximal end of said base in a direction transverse to said length of said base.
 31. A neutral field tray according to claim 26, further comprising: said surgical instrument, wherein said trough tapers in depth toward said proximal end of said trough and said surgical instrument is located within said trough with said distal end of surgical instrument located at or adjacent said distal end of said trough, and said proximal end of surgical instrument located at or adjacent said proximal end of said trough.
 32. A neutral field tray according to claim 31, wherein: said sharp at said distal end of said instrument is fully recessed in said trough.
 33. A neutral field tray according to claim 32, wherein: said handle at said proximal end of said instrument is at least partially protruding above said base so as to facilitate access to said handle by a user without exposing the user to said sharp. 